dsh-aov-up: AOV Improvement Estimation

The DeepSeek Harness plugin `dsh-aov-up` is specifically designed for estimating improvements in average order value (AOV). Implemented in pure Node.js and requiring no network access, it performs precise local calculations and returns detailed results. Its runtime dependencies are `@deepseek-ai/cordis` and `@deepseek-ai/dsh-tools`. The plugin runs with the current process’s permissions, making it suitable for offline numerical reasoning scenarios in the DSH ecosystem. It is recommended to review the source code before use.